[1] It is an integral part of railway Pan-European Corridor X running from Salzburg and Ljubljana towards Skopje and Thessaloniki.

[2][3] The line is used for passenger (regional and international) and freight traffic.

The M103 railway is electrified using a 25 kV 50 Hz AC overhead line system and single-tracked.

[10] Because of the unsatisfactory technical condition of the track on the route, major reconstruction of the corridor (including the construction of the second, parallel track along entire route) is scheduled to be carried out between 2024 and 2029.

[11] Media related to M103 railway (Croatia) at Wikimedia Commons